Tube mounting



March 7, 1950 R. C. KENNEDY TUBE MOUNTING 2 Sheets-Sheet 1 Filed Sept. 6, 1946 lNVENQR )P ATTORNEY March 7, 1950 R. c. KENNEDY 2,499,589

TUBE MOUNTING Filed Sept. 6, 1946 2 Sheets-Sheet 2 INVENTOR mil aikmly BY ATTORNEY Patented Mar. 7, 1950 TUBE MOUNTING Ralph C. Kennedy, Orangeburg, N. 2., assignor to Radio Corporation of America, a corporation .of Delaware Application September s, 1946, Serial No. 695,314

. 6 Claims. (01. 25047.5)

This invent on relates to mountings for subminiature tubes.

Sub-miniature tubes have recently been develo ed and generally have a length of approximately 1% inches and a d ameter of approximately of an inch. These tubes, at the present time, have no termina pins, but merely wires which extend through the base of the tube and connect to the e ectrodes within the glass envelope of the tube. Difficu t es are experienced in attempting to mount these tubes and to connect the terminal leads to external circuits. It has been the practice in the past, when using these tubes in the nose of an ex osive shell, to rigidly mount the tube by embedding it in wax. Tubes have been used in this way in connection with the now well known proximity fuse for detonating a shell at a predetermined distance from an object. When it is attempted to use these subminiature tubes in radio sets, it is not feasible to embed these tubes in wax and problems arise involving the mounting of these tubes, their shielding, and electrically connecting the tubes to associated circuits.

An object of the present invention is to provide a novel mechanical construction for mounting a plurality of sub-miniature tubes on a multiterminal plug, so as to provide a compact, lightweight and portable assemblage. Another object of the present invention is to provide a mounting and terminal construction for a plurality of sub-miniature tubes, which also functions to shield the tubes from each other and from external electrostat c fields.

A further object is to provide an extremely compact and lightweight mounting arrangement for a plurality of sub-miniature tubes, which can be carried in a person's pocket, and which can be readily replaced as an integral unit, quickly and easily.

A more detailed description of the invention follows in conjunction with the drawing wherein:

Fig. 1 illustrates an exploded view of the various elements which make-up one embodiment of a mounting assemblage for a plurality of subrcriiiniature tubes, in accordance with the inven- Fig. 2 illustrates the assembled elements of Fig. 1, ready for use in an electronic device whether a transmitter, receiver, amplifier, or measuring instrument; and

Fig. 3 illustrates an alternative construction of a mounting for a plurality of sub-miniature tubes, in accordance with the invention.

Referring to Figs. 1 and 2 in more detail, there 2 are shown a plurality of sub-miniature tubes (e ectron discharge devices) l arranged side by side in the same straight row and mounted upon the male element 2 of a multi-terminal plug. Each of these sub-min ature tubes i has a length of approximately 1%; inches and a diameter of approximately of an inch, although it should be understood that the invention is independent of the physical size of the sub-miniature tubes. These tubes have a number of electrodes and may be used for performing various functions such as rectification, amplification, detection, or the production of oscillation. From the base or bottom of these tubes are a plurality of terminal leads 3 which connect with the electrodes within the glass envelopes of the tubes. These terminal leads 3 are shown soldered to the metallic terminals 4 of a molded Bakelite multi-terminal male plug element 2. Not all of the terminal leads rom the tubes 1 are shown connected to the terminals 4, in order not to unduly complicate the drawing, but it should be understood that all of the tubes l have their electrodes connected through terminal leads 3 to difierent ones of the terminals 4.

Terminals 4 extend below the bottom of the male element 2 for insertion into the socket apertures of the female plug element 5. Obviously, the socket apertures in the plug element 5 are correspondingly positioned with the terminals 4 of the male plug element 2. In order to assure the proper orientat on or positioning of the two .plug elements 2 and 5, there is provided an index or guide pin 6 of a larger size and a different shape from the terminals 4, and which is adopted to fit into the correspondingly dimensioned hole 1 in the female plug element 5.

A metallic rectangular shaped block 8, made of non-ferrous material such as aluminum, copper, brass, or any other suitable material, is used to rigidly-hold the tubes l in position and to shield them from one another and from external electrostatic fields. To achieve this result, block 8 is provided with a plurality of parallel bored holes 9 arranged in the same straight row and having such dimensions as to accommodate the tubes 1 within these holes. It is preferred that the length of the bores 9 be just suilicient to permit the tubes l to be inserted for their entire length, and that the diameter of the bores 9 be just sufficient to permit a snug fit for the tubes.

In order. to-prevent vibration of tubes l to re- .,duce mierophonics, there are provided small sponge rubber. cushioning inserts 10 which are placed within the bores 9 at the uppermost or closed ends. These inserts It will thus be in contact with the tips of the tubes I when the tubes are inserted into the metallic block 8.

In order to securely fasten the block 8 in proper spaced relation to the multi-terminal plug,

there are provided a pair of elongated screws H p which are insertable through apertures. l2, l2 in the male plug: element 2 from the bottom, and a pair of threaded holes M in the metal block 8. The washers l3, l3 assure the fact that the block 8 is properly spaced from the multi-terminal plug so that the bottom of the block 8 does not contact the terminal leads 3 nor exert excessive downward pressure upon the tubes I.

Fig. 2 illustrates the multi-terminal construction when completely assembled for use in an electronic device. In one embodiment actually constructed and successfully employed as an audio amplifier, the tubes were of the 1W5 and 1V5 types manufactured by the sylvania Electrio Products Corporation. These tubes were of thepentode type. The width of the block 8 was 3 /2 inches, the depth of this block was slightly less than an inch while the length of the block was slightly less than 1% inches. The multiterminal' plug which was used is known as 9. Howard B. Jones molded Bakelite plug and had an overall dimension for the male and female elements taken together of 3% inches by 1 inch by 1 inch, disregarding the'projecting portions of the terminals above and below the plug. The terminal connections on the multi-terminal plug extended about a A,, of an inch above and A; of an inch below the plug. The entire assemblage shown in Fig. 2, including metallic'block 8, seven sub-miniature tubes, and multi-terminal plug 2, 5 weighed about 7 oz. It will thus be seen that the mounting and shield construction for the sub-miniature tubes is extremely compact and lightweight, and can be easily carried in a person's pocket.

An advantage of the mechanical construction of the present invention lies in the fact that an entire assemblage of tubes can be simply and easily replaced merely by removing that portion of the mounting which includes the tubes I and the male plug element 2. Thus, if there is a defective tube in a radio set it will only take a matter of seconds to reolacean entire set of tubes, and wi l avoid the laborious task of searching for a particular defective tube and attemptin to resol er and replacing the defective tube.

Fig. 3 shows an alternative arrangement for mountin sub-miniature tubes in spaced relation and for s ielding them from one another and from external electrostatic fields. In Fig. 3, there is shown a rectangular metallic block 8' which minals ii to which the electrode leads extending from the bases of the tubes can be soldered. Leads to the external circuits can also be connected to these terminals H. In order to fasten the insulating strip I5 to the metallic block 8', there are provided holes l8 through which suitable screws can be inserted. Obviously, the metallic block 8' also has holes of similar size regis- ""te'ring with the holes l8-but which are threaded =to accommodate'the screws;

The sub-miniature tubes have not been shown in Fig. 3 in the interest of simplifying the drawing, but it will be understood that these tubes are insertable into bores It so that their tips extend downward while their bases are very slightly raised above or flush with the insulating strip l5. It is also preferred that suitable sponge-like cushioning. inserts ll] be used at the bottom of the bores in the block 8" which accommodates the sub miniature tubes, in order to prevent movement of the tubes within the metallic block and'reduce microphonics.

, The construction of Fig. 3 avoids the necessity for-"using a multi-ter-minal plug such as is shown in theiembodiment of Figs. 1 and 2. A disadvantage of the arrangement of Fig. 3 is that it does not permit the rapid interchange of all of the tubes as a unit which is an advantage of the construction of Figs. 1 and 2.

Although the mounting construction has been sho n in the drawing as accommodating a pluraiity of sub -miniature tubes arranged in a single row, it should be understood that the invention is not limited to such a construction since, obviously, the submiiniature tubes can be spaced in parallel rows or even around a circle and the metallic block 3 can be suitably bored to accomthe particular positioning of the subm'iniature tubes. The block 3 may thus be of any suitable shape; for example, cylindrical which would be the preferred arrangement where the tubes are arranged in a circle. If the block 8 is cylindrical, it would be preferred that it be in the form of a hollow cylinder of sufiicient thickness to permit the tubes to be inserted into the bores, the hollow central portion of the block serving to minimize the weight.

What is claimed is:

1. A mounting construction for a plurality of sub-miniature electron discharge devices of the type which is devoid of rigid terminal prongs or pins, comprising a non-ferrous block having a metallic surface and provided with a plurality of spaced parallel bores therein Whose widths are slightly larger than the widths of said devices for snugly accommodating said devices substantially completely within the bores, said bores being open at one end only, and vibration cushioning material located at the closed ends of said bores for reducing microphonics in said sub-miniature devices, and a plurality of raised terminal connections for fixed association with the electrode terminals of said devices, said raised terminal connections being substantially parallel to the longitudinal axes of said devices.

2. A mounting construction for a plurality of sub-miniature electron discharge devices of the type which is devoid of rigid terminal prongs or pins, comprising a block having a non-ferrous 0 metallic surface and provided with a plurality of spaced bores therein Whose widths are slightly larger than the widths of said devices for snugly accommodating said device substantially completely within the bores, said bores being open at one end only, and insulating material secured to said block at the open ends of said bores, said insulating material having terminals for connec tion with the leads extending from the envelopes of said devices.

3. A mounting construction for a plurality of sub-miniature electron discharge devices, comprising a block having a non-ferrous metallic surface and provided with a plurality of spaced bores therein Whose widths are slightly larger 75than the widths of said devices for snugly-accommodating said devices substantially completely within the bores, said bores being open at one end only, and insulating material secured to the block at the open ends of said bores and having apertures registering with the opening in said bores, said insulating material also having terminal connections.

4. A mounting construction for a plurality of sub-miniature electron discharge devices, comprising a metallic bloc having a plurality of spaced bores therein whose widths are slightly larger than the widths of said devices for snugly accommodating said devices substantially completely within the bores, a multiple terminal plug at one end of said block, and means rigidly securing said block to said plug in spaced relation thereto.

5. A mounting construction for a plurality of sub-miniature electron discharge devices, comprising a block having a metallic surface and provided with a plurality of spaced bores therein whose widths are slightly larger than the widths of said devices for snugly accommodating said devices substantially completely within the bores, said bores being open at one end only, vibration clamping material located at the closed ends of said bores, a multiple terminal plug near said one end of said block, and means rigidly securing said block to said plug in spaced relation thereto, said means including spacing washers.

6. A compact, lightweight, portable and easily 8 replaceable subminiature tube assemblage, comprising a plurality of sub-miniature tubes of the type which is devoid of rigid terminal prongs or pins, and in physically parallel relation and sim; ilarly mounted at one end upon a multiple terminal element, said element comprising the male portion of a multiple terminal plug, a metallic block having a plurality of spaced bores therein for snugly accommodating said tubes substantially completely within said bores, and means rigidly securing said block to said terminal element in spaced relation thereto.

RALPH C. KENNEDY.

BEFEEENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 832,181 Dean Oct. 2, 1906 1,925,558 Foster Sept. 5, 1933 2,045,648 Henry et al June 30, 1936 2,398,626 Del Camp Apr. 16, 1946 2,424,683 Ei'tel et al July 29, 1947 2,431,198 Posen Nov. 18, 1947 2,439,412 Mitchell Apr. 13, 1948 FOREIGN PATENTS Number Country Date 515,551 Great Britain Dec. 7, 1939 

